AUTHORS Alejandro Escalona  Institute for Geo- physics, Jackson School of Geosciences, Uni- versity of Texas at Austin, 4412 Spicewood Springs Road, Building 600, Austin, Texas, 78759; escalona@utig.ig.utexas.edu Alejandro Escalona is a postdoctoral researcher at the Institute for Geophysics, University of Texas at Austin. He received his Ph.D. in ge- ology at the University of Texas at Austin in 2003, where he focused on the stratigraphic and structural evolution of the Maracaibo Basin, Venezuela. He is currently interpreting re- gional seismic and well data from offshore Venezuela to link offshore and on-land Cenozoic depocenters. Paul Mann  Institute for Geophysics, Jack- son School of Geosciences, University of Texas at Austin, 4412 Spicewood Springs Road, Building 600, Austin, Texas, 78759; paulm@utig.ig.utexas.edu Paul Mann is a senior research scientist at the Institute for Geophysics, University of Texas at Austin. He received his Ph.D. in geology at the State University of New York in 1983 and has published widely on the tectonics of strike- slip, rift, and collision-related sedimentary ba- sins. His current focus area of research is the interplay of tectonics, sedimentation, and hydro- carbon occurrence in Venezuela and Trinidad. ACKNOWLEDGEMENTS We thank Petro ´ leos de Venezuela, S. A., for providing seismic and well data used in this study. This work was supported by Grant 40499-AC8 from the Donors of the Petroleum Research Fund of the American Chemical Society to P. Mann. We thank S. Talukdar, D. Goddard, and R. Erlich for valuable re- views. The authors acknowledge the financial support for publication costs provided by the University of Texas at Austin’s Geology Founda- tion and the Jackson School of Geosciences. University of Texas, Institute for Geophysics Contribution 1775. Editor’s Note Color versions of figures may be seen in the online version of this article. An overview of the petroleum system of Maracaibo Basin Alejandro Escalona and Paul Mann ABSTRACT The geologically complex Maracaibo Basin in northwestern Vene- zuela is one of the most prolific hydrocarbon basins in the world. Having a basinal area of 50,000 km 2 (19,300 mi 2 ), the basin has produced more than 30 billion bbl of oil, with estimated re- coverable oil reserves of more than 44 billion bbl. The central elements of the petroleum system of the basin include (1) a world- class source rock (Upper Cretaceous La Luna Formation), depos- ited on a shelf-to-slope environment under anoxic conditions and modified by intermittent oxygenated periods and tectonic events; (2) high-quality clastic reservoir rocks deposited in Eocene and Miocene fluviodeltaic settings; (3) two main periods of rapid tec- tonic subsidence responsible for two pulses of voluminous hydro- carbon generation, first, during Paleogene Caribbean–South Ameri- can oblique plate collision and, second, during the Neogene uplift of the Sierra de Perija ´–Me ´rida Andes; and (4) lateral and vertical migration of oil along strike-slip, normal, and inverted faults, as well as a regional unconformity of late Eocene–Oligocene age. The maturation, migration, and trapping of hydrocarbons were closely controlled by the tectonic evolution of the Maracaibo Basin. During the Paleogene, the development of a foredeep along the northeastern margin of the basin and the strike-slip reactivation of the rift-related Jurassic faults on the Maracaibo platform controlled the early structural setting of the source and reservoir rocks. Hy- drocarbons migrated updip from source rocks beneath the north- northeastern margin of the basin along north-south strike-slip faults and into overlying Eocene clastic reservoirs in the south-central parts of the basin. The second period of the Maracaibo Basin petroleum system developed during subaerial exposure of most of the Mara- caibo Basin during Oligocene – Miocene uplift of the adjacent Sierra de Perija ´ and Me ´rida Andes. Uplift of mountain ranges surround- ing the basin folded and depressed the interior of the basin to form the extensive Maracaibo syncline. Because of the formation of the Maracaibo syncline, oil generation began in the central and southern parts of the synclinal basin and migrated northward. Hydrocarbons migrated up the flanks of the Maracaibo syncline along reactivated AAPG Bulletin, v. 90, no. 4 (April 2006), pp. 657–678 657 Copyright #2006. The American Association of Petroleum Geologists. All rights reserved. Manuscript received February 19, 2005; provisional acceptance April 21, 2005; revised manuscript received September 28, 2005; final acceptance October 14, 2005. DOI:10.1306/10140505038